1: potassium hydroxide / ethanol; water / |Large scale 2: ethyl acetate / 2 h / 60 - 65 °C / |Large scale 3: 3-nitro-phenyl boronic acid / anhydrous xylene / 24 h / 40 °C / |Reflux 4: dimethylsulfide borane complex / tetrahydrofuran / 16 h / 0 - 25 °C View Scheme

1: ethyl acetate / 2 h / 60 - 65 °C / |Large scale 2: 3-nitro-phenyl boronic acid / anhydrous xylene / 24 h / 40 °C / |Reflux 3: dimethylsulfide borane complex / tetrahydrofuran / 16 h / 0 - 25 °C View Scheme

1: sodium t-butanolate / tert-butyl alcohol / 3.5 h / 20 - 25 °C / |Large scale 2: potassium hydroxide / ethanol; water / |Large scale 3: ethyl acetate / 2 h / 60 - 65 °C / |Large scale 4: 3-nitro-phenyl boronic acid / anhydrous xylene / 24 h / 40 °C / |Reflux 5: dimethylsulfide borane complex / tetrahydrofuran / 16 h / 0 - 25 °C View Scheme

1: 3-nitro-phenyl boronic acid / anhydrous xylene / 24 h / 40 °C / |Reflux 2: dimethylsulfide borane complex / tetrahydrofuran / 16 h / 0 - 25 °C View Scheme